Around 700, 000 potentially contaminated eggs have been distributed throughout the UK, it has been revealed.
Millions of eggs are feared to have been tainted with traces of the ‘potentially harmful’ pesticide Fipronil which the World Health Organisation says is moderately toxic and can cause organ damage if consumed in large quantities.
Around 700,000 of these eggs have been sent to the UK from Dutch farms - far higher than the 21, 000 first estimated.
The FSA said products affected were likely to be processed foods, such as sandwich fillings, that contained eggs among other ingredients.
The organisation added that some of the products containing the eggs had a short shelf life and will have already been consumed but other foods were still within the expiry date and are now being withdrawn from sale.
A spokesperson said investigations indicated it was "very unlikely" that the eggs posed a risk to public health.
It is illegal to use pesticides at a poultry farm.
Dutch and Belgian authorities are now carrying out raids as part of a criminal investigation into how egg-laying chickens came into contact with it.
They have reportedly pinned the source of the issue to a supplier of cleaning products in the Netherlands.